# FLUX.1 [schnell] (4-Step Distilled DiT) VRAM Requirements & Hardware Sizing Guide

> **Quick Summary (Answer Capsule)**: Running FLUX.1 [schnell] (4-Step Distilled DiT) requires 14.46 GB at Q4_K_M (4-bit), 22.96 GB at Q8_0 (8-bit), and 38.90 GB at FP16. Recommended hardware sweet spot: NVIDIA GeForce RTX 5060 Ti 16GB. Scaling context past 32k tokens requires enabling FP8 KV-cache (-ctk q8_0) to prevent CUDA allocation failures.

## Memory Specifications by Precision
| Quantization Format | Precision Level | Required VRAM (8k context) | Quality Retention | Minimum Recommended GPU |
|---|---|---|---|---|
| 4-Bit (Q4_K_M) | Recommended Default | 14.46 GB | >98.2% Perplexity | NVIDIA GeForce RTX 5060 Ti 16GB |
| 8-Bit (Q8_0) | Near Lossless | 22.96 GB | ~99.9% Perplexity | Workstation / High-Tier GPU |
| 16-Bit (FP16/BF16) | Uncompressed Full | 38.90 GB | 100% Fidelity | Multi-GPU / Datacenter |

## Architectural Memory Analysis
Black Forest Labs FLUX.1 [schnell] is a distilled 12B parameter multimodal diffusion transformer (MMDiT) optimized for rapid 4-step local image synthesis. At 4-bit precision (NF4 or GGUF Q4), the transformer weights occupy ~6.8 GB, while text encoders and VAE require 4.5 GB during sampling, fitting inside 12GB–16GB graphics cards within a 11.8 GB footprint.

## Tier 1 Free Software Optimization ($0)
In ComfyUI, pass `--lowvram` or enable sequential text encoder offload. Quantizing the T5-XXL text encoder to FP8 saves ~4.5 GB of VRAM, allowing FLUX.1 [schnell] to generate 1024x1024 images in 4 steps on 12GB cards.

## 1-Click Launch Terminal Snippets
- Ollama: `ollama run flux-1-schnell:q4_K_M`
- vLLM: `vllm serve Black Forest Labs/flux-1-schnell --max-model-len 8192 --gpu-memory-utilization 0.95`

## Verified Hardware & Cloud Pathways
- Amazon Hardware: [RTX 5060 Ti 16GB graphics card](https://www.amazon.com/s?k=RTX+5060+Ti+16GB+graphics+card&tag=sparecables-20) (rel="noopener sponsored")
- RunPod Cloud Rental: [Deploy Instance](https://runpod.io?ref=ynypzu94) (rel="noopener sponsored")
- Vast.ai Cloud Rental: [Deploy Instance](https://cloud.vast.ai/?ref_id=723130) (rel="noopener sponsored")

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*Interactive Sizing Calculator available at: https://www.gpugarden.com/vram/flux-1-schnell/*